I use the two rope method for the tree hanging rope, seems easier too me as well, and allows for Azalea's modification.
 I remember Mad Mat's recommendation about using a lighter heave line in case you snag, and had that in mind when I contemplated the switch to the Dacron line.  I still think I'll keep the 1/4" for the haul rope, easier on the hands.  If you don't have the 3 pulley set-up, and your hoisting a heavy food pack, you owe yourself too make the switch. Even a small person, with minimal effort can easily lift 90# with ease.
Thanks for info on Dacron kite line ;D